The present invention relates to a device for applying sealing labels to containers.
In particular, the present invention relates to a device of the above type for applying so-called "government stamps" to the top portions of cigarette packets.
U.S. Pat. No. 4,718,216 relates to a device, designed to operate in conjunction with a cigarette packing machine with two wrapping lines, wherein the packets of cigarettes coming off each wrapping line are gradually stacked vertically, by an intermittent upward-feed lift member, in the vicinity of a labeling device.
Each labeling device substantially comprises a suction roller for successively feeding the labels adhering to its periphery to a gumming device, and then to a labeling station where the labels are applied to the bottom packet in the stack formed by the lift member.
Each suction roller has a number of peripheral fork elements movable radially in relation to the roller and presenting prongs on the ends of which the gummed label is retained by suction.
When applying the label to the bottom packet in the stack, the rest of the stack must be raised off the bottom packet by a sufficient distance to enable the fork element on the roller to fit between the bottom packet and the stack, and the prongs of the fork element to enclose the end of the packet. As a result, prior to the arrival of the next packet for labeling, each labeled packet must be raised, together with the rest of the stack, by a distance considerably greater than the thickness of the packet; which movement, to prevent damaging the packets by subjecting them to severe mechanical stress, is performed relatively slowly, thus seriously impairing the operating speed of the device and hence the packing machine as a whole.
Moreover, as the fork element is withdrawn from the labeled packet, the friction produced by the fork element frequently results in either partial or total removal of the label.